Analytical Chemistry intercomparison between University of La Laguna (ULL), University of Las Palmas (ULP), and Norwegian Institute for Water Research (NIVA)

Abstract

As a part of the evaluation of chemical procedures applied in the baseline survey at two power plant locations at the Canary Islands, an intercomparison was organized between the University of La Lugana (ULL), the University of Las Palmas (ULP), and Norwegian Institute for Water Research (NIVA). The chemical variables analyzed were ammonia, nitrate+nitrite, and heavy metals in sea water, and heavy metals and PAH (polyaromatic hydrocarbons) in sediments and biological materials. One of the sea water samples was a certified refernce material, and the others were natural sea water spiked with known amounts of the topical variables. The sediment and biological material was collected outside the Canary Islands. Varying comparability is in part due to the fact that other methods than agreed upon have been used by the laboratories, and in part that analytical problems have been dominating for the water samples. For heavy metals it is strongly recommended to use the freon extraction method. This method requires that the laboratories must established a lot of experience with the handling technique, and thus are able to control the contamination problems. The comparability between the results for the biological material is acceptable. It is recommended that the laboratories document the analytical quality by the use of certified reference materials, and by participation in the Quasimeme intercomparisons.